/* * Copyright 2025 Edward V. Emelianov . * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the * GNU General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program. If not, see . */ #include #include #include "BMP280.h" #include "i2c.h" #include "sensors_private.h" /** * BMP280 registers */ #define BMP280_REG_HUM_LSB 0xFE #define BMP280_REG_HUM_MSB 0xFD #define BMP280_REG_HUM (BMP280_REG_HUM_MSB) #define BMP280_REG_TEMP_XLSB 0xFC /* bits: 7-4 */ #define BMP280_REG_TEMP_LSB 0xFB #define BMP280_REG_TEMP_MSB 0xFA #define BMP280_REG_TEMP (BMP280_REG_TEMP_MSB) #define BMP280_REG_PRESS_XLSB 0xF9 /* bits: 7-4 */ #define BMP280_REG_PRESS_LSB 0xF8 #define BMP280_REG_PRESS_MSB 0xF7 #define BMP280_REG_PRESSURE (BMP280_REG_PRESS_MSB) #define BMP280_REG_ALLDATA (BMP280_REG_PRESS_MSB) // all data: P, T & H #define BMP280_REG_CONFIG 0xF5 /* bits: 7-5 t_sb; 4-2 filter; 0 spi3w_en */ #define BMP280_REG_CTRL 0xF4 /* bits: 7-5 osrs_t; 4-2 osrs_p; 1-0 mode */ #define BMP280_REG_STATUS 0xF3 /* bits: 3 measuring; 0 im_update */ #define BMP280_STATUS_MSRNG (1<<3) // measuring flag #define BMP280_STATUS_UPDATE (1<<0) // update flag #define BMP280_REG_CTRL_HUM 0xF2 /* bits: 2-0 osrs_h; */ #define BMP280_REG_RESET 0xE0 #define BMP280_RESET_VALUE 0xB6 #define BMP280_REG_ID 0xD0 #define BMP280_REG_CALIBA 0x88 #define BMP280_CALIBA_SIZE (26) // 26 bytes of calibration registers sequence from 0x88 to 0xa1 #define BMP280_CALIBB_SIZE (7) // 7 bytes of calibration registers sequence from 0xe1 to 0xe7 #define BMP280_REG_CALIB_H1 0xA1 // dig_H1 #define BMP280_REG_CALIBB 0xE1 #define BMP280_MODE_FORSED (1) // force single measurement #define BMP280_MODE_NORMAL (3) // run continuosly #define BMP280_CHIP_ID 0x58 #define BME280_CHIP_ID 0x60 typedef enum{ // K for filtering: next = [prev*(k-1) + data_ADC]/k BMP280_FILTER_OFF = 0, // k=1, no filtering BMP280_FILTER_2 = 1, // k=2, 2 samples to reach >75% of data_ADC BMP280_FILTER_4 = 2, // k=4, 5 samples BMP280_FILTER_8 = 3, // k=8, 11 samples BMP280_FILTER_16 = 4, // k=16, 22 samples } BMP280_Filter; typedef enum{ // Number of oversampling BMP280_NOMEASUR = 0, BMP280_OVERS1 = 1, BMP280_OVERS2 = 2, BMP280_OVERS4 = 3, BMP280_OVERS8 = 4, BMP280_OVERS16 = 5, } BMP280_Oversampling; typedef struct{ BMP280_Filter filter; // filtering BMP280_Oversampling p_os; // oversampling for pressure BMP280_Oversampling t_os; // -//- temperature BMP280_Oversampling h_os; // -//- humidity uint8_t ID; // identificator uint8_t regctl; // control register base value [(params.t_os << 5) | (params.p_os << 2)] } BPM280_params_t; // default parameters for initialized s->privdata static const BPM280_params_t defparams = { .filter = BMP280_FILTER_4, .p_os = BMP280_OVERS16, .t_os = BMP280_OVERS16, .h_os = BMP280_OVERS16, .ID = 0 }; typedef struct { // temperature uint16_t dig_T1; // 0x88 (LSB), 0x98 (MSB) int16_t dig_T2; // ... int16_t dig_T3; // pressure uint16_t dig_P1; int16_t dig_P2; int16_t dig_P3; int16_t dig_P4; int16_t dig_P5; int16_t dig_P6; int16_t dig_P7; int16_t dig_P8; int16_t dig_P9; // 0x9e, 0x9f // humidity (partially calculated from EEE struct) uint8_t unused; // 0xA0 uint8_t dig_H1; // 0xA1 int16_t dig_H2; // 0xE1... uint8_t dig_H3; // only from EEE uint16_t dig_H4; uint16_t dig_H5; int8_t dig_H6; // calibration done uint8_t calibrated; // parameters BPM280_params_t params; } __attribute__ ((packed)) CaliData_t; /* // setters for `params` void BMP280_setfilter(sensor_t *s, BMP280_Filter f){ ((CaliData_t*)s->privdata)->params.filter = f; } void BMP280_setOSt(sensor_t *s, BMP280_Oversampling os){ ((CaliData_t*)s->privdata)->params.t_os = os; } void BMP280_setOSp(sensor_t *s, BMP280_Oversampling os){ ((CaliData_t*)s->privdata)->params.p_os = os; } void BMP280_setOSh(sensor_t *s, BMP280_Oversampling os){ ((CaliData_t*)s->privdata)->params.h_os = os; }*/ // get compensation data, return 1 if OK static int readcompdata(sensor_t *s){ FNAME(); CaliData_t *CaliData = (CaliData_t*)s->privdata; if(!i2c_read_data8(BMP280_REG_CALIBA, BMP280_CALIBA_SIZE, (uint8_t*)CaliData)){ DBG("Can't read calibration A data"); return FALSE; } if(CaliData->params.ID == BME280_CHIP_ID){ uint8_t EEE[BMP280_CALIBB_SIZE] = {0}; if(!i2c_read_reg8(BMP280_REG_CALIB_H1, &CaliData->dig_H1)){ WARNX("Can't read dig_H1"); return FALSE; } if(!i2c_read_data8(BMP280_REG_CALIBB, BMP280_CALIBB_SIZE, EEE)){ WARNX("Can't read rest of dig_Hx"); return FALSE; } // E5 is divided by two parts so we need this sex CaliData->dig_H2 = (EEE[1] << 8) | EEE[0]; CaliData->dig_H3 = EEE[2]; CaliData->dig_H4 = (EEE[3] << 4) | (EEE[4] & 0x0f); CaliData->dig_H5 = (EEE[5] << 4) | (EEE[4] >> 4); CaliData->dig_H6 = EEE[6]; } CaliData->calibrated = 1; DBG("Calibration rdy"); return TRUE; } // do a soft-reset procedure static int s_reset(){ if(!i2c_write_reg8(BMP280_REG_RESET, BMP280_RESET_VALUE)){ DBG("Can't reset\n"); return FALSE; } return TRUE; } // read compensation data & write registers static int s_init(sensor_t *s){ s->status = SENS_NOTINIT; uint8_t devid; if(!i2c_read_reg8(BMP280_REG_ID, &devid)){ DBG("Can't read BMP280_REG_ID"); return FALSE; } DBG("Got device ID: 0x%02x", devid); if(devid != BMP280_CHIP_ID && devid != BME280_CHIP_ID){ WARNX("Not BM[P/E]280\n"); return FALSE; } if(!s_reset()) return FALSE; // wait whlie update done uint8_t reg = BMP280_STATUS_UPDATE; while(reg & BMP280_STATUS_UPDATE){ // wait while update is done if(!i2c_read_reg8(BMP280_REG_STATUS, ®)){ DBG("Can't read status"); return FALSE; } } // allocate calibration and other data if need if(!s->privdata){ s->privdata = calloc(1, sizeof(CaliData_t)); ((CaliData_t*)s->privdata)->params = defparams; // and init default parameters DBG("ALLOCA"); }else ((CaliData_t*)s->privdata)->calibrated = 0; BPM280_params_t *params = &((CaliData_t*)s->privdata)->params; params->ID = devid; if(!readcompdata(s)){ DBG("Can't read calibration data\n"); return FALSE; }else{ #ifdef EBUG CaliData_t *CaliData = (CaliData_t*)s->privdata; DBG("T: %d, %d, %d", CaliData->dig_T1, CaliData->dig_T2, CaliData->dig_T3); DBG("\P: %d, %d, %d, %d, %d, %d, %d, %d, %d", CaliData->dig_P1, CaliData->dig_P2, CaliData->dig_P3, CaliData->dig_P4, CaliData->dig_P5, CaliData->dig_P6, CaliData->dig_P7, CaliData->dig_P8, CaliData->dig_P9); if(devid == BME280_CHIP_ID){ // H compensation DBG("H: %d, %d, %d, %d, %d, %d", CaliData->dig_H1, CaliData->dig_H2, CaliData->dig_H3, CaliData->dig_H4, CaliData->dig_H5, CaliData->dig_H6); } #endif } // write filter configuration reg = params->filter << 2; if(!i2c_write_reg8(BMP280_REG_CONFIG, reg)){ DBG("Can't save filter settings\n"); return FALSE; } reg = (params->t_os << 5) | (params->p_os << 2); // oversampling for P/T, sleep mode if(!i2c_write_reg8(BMP280_REG_CTRL, reg)){ DBG("Can't write settings for P/T\n"); return FALSE; } params->regctl = reg; if(devid == BME280_CHIP_ID){ // write CTRL_HUM only AFTER CTRL! reg = params->h_os; if(!i2c_write_reg8(BMP280_REG_CTRL_HUM, reg)){ DBG("Can't write settings for H\n"); return FALSE; } } DBG("OK, inited"); s->status = SENS_RELAX; return TRUE; } // start measurement, @return 1 if all OK static int s_start(sensor_t *s){ if(!s->privdata || s->status == SENS_BUSY || ((CaliData_t*)s->privdata)->calibrated == 0) return FALSE; uint8_t reg = ((CaliData_t*)s->privdata)->params.regctl | BMP280_MODE_FORSED; // start single measurement if(!i2c_write_reg8(BMP280_REG_CTRL, reg)){ DBG("Can't write CTRL reg\n"); return FALSE; } s->status = SENS_BUSY; return TRUE; } // return T in degC static inline float compTemp(sensor_t *s, int32_t adc_temp, int32_t *t_fine){ CaliData_t *CaliData = (CaliData_t*)s->privdata; int32_t var1, var2; var1 = ((((adc_temp >> 3) - ((int32_t) CaliData->dig_T1 << 1))) * (int32_t) CaliData->dig_T2) >> 11; var2 = (((((adc_temp >> 4) - (int32_t) CaliData->dig_T1) * ((adc_temp >> 4) - (int32_t) CaliData->dig_T1)) >> 12) * (int32_t) CaliData->dig_T3) >> 14; *t_fine = var1 + var2; return ((*t_fine * 5 + 128) >> 8) / 100.; } // return P in Pa static inline double compPres(sensor_t *s, int32_t adc_press, int32_t fine_temp){ CaliData_t *CaliData = (CaliData_t*)s->privdata; int64_t var1, var2, p; var1 = (int64_t) fine_temp - 128000; var2 = var1 * var1 * (int64_t) CaliData->dig_P6; var2 = var2 + ((var1 * (int64_t) CaliData->dig_P5) << 17); var2 = var2 + (((int64_t) CaliData->dig_P4) << 35); var1 = ((var1 * var1 * (int64_t) CaliData->dig_P3) >> 8) + ((var1 * (int64_t) CaliData->dig_P2) << 12); var1 = (((int64_t) 1 << 47) + var1) * ((int64_t) CaliData->dig_P1) >> 33; if (var1 == 0){ return 0; // avoid exception caused by division by zero } p = 1048576 - adc_press; p = (((p << 31) - var2) * 3125) / var1; var1 = ((int64_t) CaliData->dig_P9 * (p >> 13) * (p >> 13)) >> 25; var2 = ((int64_t) CaliData->dig_P8 * p) >> 19; p = ((p + var1 + var2) >> 8) + ((int64_t) CaliData->dig_P7 << 4); return p/25600.; // hPa } // return H in percents static inline double compHum(sensor_t *s, int32_t adc_hum, int32_t fine_temp){ CaliData_t *CaliData = (CaliData_t*)s->privdata; int32_t v_x1_u32r; v_x1_u32r = fine_temp - (int32_t) 76800; v_x1_u32r = ((((adc_hum << 14) - (((int32_t)CaliData->dig_H4) << 20) - (((int32_t)CaliData->dig_H5) * v_x1_u32r)) + (int32_t)16384) >> 15) * (((((((v_x1_u32r * ((int32_t)CaliData->dig_H6)) >> 10) * (((v_x1_u32r * ((int32_t)CaliData->dig_H3)) >> 11) + (int32_t)32768)) >> 10) + (int32_t)2097152) * ((int32_t)CaliData->dig_H2) + 8192) >> 14); v_x1_u32r = v_x1_u32r - (((((v_x1_u32r >> 15) * (v_x1_u32r >> 15)) >> 7) * ((int32_t)CaliData->dig_H1)) >> 4); v_x1_u32r = v_x1_u32r < 0 ? 0 : v_x1_u32r; v_x1_u32r = v_x1_u32r > 419430400 ? 419430400 : v_x1_u32r; return (v_x1_u32r >> 12)/1024.; } static sensor_status_t s_process(sensor_t *s){ uint8_t reg; if(s->status != SENS_BUSY) goto ret; if(!i2c_read_reg8(BMP280_REG_STATUS, ®)) return (s->status = SENS_ERR); DBG("stat=0x%02X", reg); if(reg & BMP280_STATUS_MSRNG) goto ret; // OK, measurements done -> get and calculate data CaliData_t *CaliData = (CaliData_t*)s->privdata; uint8_t ID = CaliData->params.ID; uint8_t datasz = 8; // amount of bytes to read uint8_t data[8]; if(ID == BMP280_CHIP_ID) datasz = 6; // no humidity if(!i2c_read_data8(BMP280_REG_ALLDATA, datasz, data)){ DBG("Can't read data"); return (s->status = SENS_ERR); } int32_t p = (data[0] << 12) | (data[1] << 4) | (data[2] >> 4); DBG("puncomp = %d", p); int32_t t = (data[3] << 12) | (data[4] << 4) | (data[5] >> 4); DBG("tuncomp = %d", t); int32_t t_fine; s->data.T = compTemp(s, t, &t_fine); DBG("tfine = %d", t_fine); s->data.P = compPres(s, p, t_fine); if(ID == BME280_CHIP_ID){ int32_t h = (data[6] << 8) | data[7]; DBG("huncomp = %d", h); s->data.H = compHum(s, h, t_fine); } s->status = SENS_RDY; ret: return s->status; } static sensor_props_t s_props(sensor_t *s){ sensor_props_t p = {.T = 1, .P = 1}; if(s && s->privdata){ if(((CaliData_t*)s->privdata)->params.ID == BME280_CHIP_ID) p.H = 1; } return p; } static int s_heater(sensor_t _U_ *s, int _U_ on){ return FALSE; } sensor_t BMP280 = { .name = "BMP280", .address = 0x76, .status = SENS_NOTINIT, .init = s_init, .start = s_start, .heater = s_heater, .process = s_process, .properties = s_props, }; sensor_t BME280 = { .name = "BME280", .address = 0x76, .status = SENS_NOTINIT, .init = s_init, .start = s_start, .heater = s_heater, .process = s_process, .properties = s_props, };